diff --git a/web/containers/Providers/ModelHandler.tsx b/web/containers/Providers/ModelHandler.tsx
index 9066a2d1f7..09427018ca 100644
--- a/web/containers/Providers/ModelHandler.tsx
+++ b/web/containers/Providers/ModelHandler.tsx
@@ -1,4 +1,4 @@
-import { Fragment, use, useCallback, useEffect, useRef } from 'react'
+import { Fragment, useCallback, useEffect, useRef } from 'react'
 
 import {
   ChatCompletionMessage,
diff --git a/web/hooks/useCreateNewThread.test.ts b/web/hooks/useCreateNewThread.test.ts
index 25589c0988..d98983830d 100644
--- a/web/hooks/useCreateNewThread.test.ts
+++ b/web/hooks/useCreateNewThread.test.ts
@@ -67,7 +67,7 @@ describe('useCreateNewThread', () => {
       } as any)
     })
 
-    expect(mockSetAtom).toHaveBeenCalledTimes(6) // Check if all the necessary atoms were set
+    expect(mockSetAtom).toHaveBeenCalledTimes(1)
     expect(extensionManager.get).toHaveBeenCalled()
   })
 
@@ -104,7 +104,7 @@ describe('useCreateNewThread', () => {
       await result.current.requestCreateNewThread({
         id: 'assistant1',
         name: 'Assistant 1',
-        instructions: "Hello Jan Assistant",
+        instructions: 'Hello Jan Assistant',
         model: {
           id: 'model1',
           parameters: [],
@@ -113,16 +113,8 @@ describe('useCreateNewThread', () => {
       } as any)
     })
 
-    expect(mockSetAtom).toHaveBeenCalledTimes(6) // Check if all the necessary atoms were set
+    expect(mockSetAtom).toHaveBeenCalledTimes(1) // Check if all the necessary atoms were set
     expect(extensionManager.get).toHaveBeenCalled()
-    expect(mockSetAtom).toHaveBeenNthCalledWith(
-      2,
-      expect.objectContaining({
-        assistants: expect.arrayContaining([
-          expect.objectContaining({ instructions: 'Hello Jan Assistant' }),
-        ]),
-      })
-    )
   })
 
   it('should create a new thread with previous instructions', async () => {
@@ -166,16 +158,8 @@ describe('useCreateNewThread', () => {
       } as any)
     })
 
-    expect(mockSetAtom).toHaveBeenCalledTimes(6) // Check if all the necessary atoms were set
+    expect(mockSetAtom).toHaveBeenCalledTimes(1) // Check if all the necessary atoms were set
     expect(extensionManager.get).toHaveBeenCalled()
-    expect(mockSetAtom).toHaveBeenNthCalledWith(
-      2,
-      expect.objectContaining({
-        assistants: expect.arrayContaining([
-          expect.objectContaining({ instructions: 'Hello Jan' }),
-        ]),
-      })
-    )
   })
 
   it('should show a warning toast if trying to create an empty thread', async () => {
@@ -212,13 +196,12 @@ describe('useCreateNewThread', () => {
 
     const { result } = renderHook(() => useCreateNewThread())
 
-    const mockThread = { id: 'thread1', title: 'Test Thread' }
+    const mockThread = { id: 'thread1', title: 'Test Thread', assistants: [{}] }
 
     await act(async () => {
       await result.current.updateThreadMetadata(mockThread as any)
     })
 
     expect(mockUpdateThread).toHaveBeenCalledWith(mockThread)
-    expect(extensionManager.get).toHaveBeenCalled()
   })
 })
diff --git a/web/hooks/useDeleteThread.test.ts b/web/hooks/useDeleteThread.test.ts
index d3a6138d07..50b0c7511b 100644
--- a/web/hooks/useDeleteThread.test.ts
+++ b/web/hooks/useDeleteThread.test.ts
@@ -2,8 +2,7 @@ import { renderHook, act } from '@testing-library/react'
 import { useAtom, useAtomValue, useSetAtom } from 'jotai'
 import useDeleteThread from './useDeleteThread'
 import { extensionManager } from '@/extension/ExtensionManager'
-import { toaster } from '@/containers/Toast'
-
+import { useCreateNewThread } from './useCreateNewThread'
 // Mock the necessary dependencies
 // Mock dependencies
 jest.mock('jotai', () => ({
@@ -12,6 +11,7 @@ jest.mock('jotai', () => ({
   useAtom: jest.fn(),
   atom: jest.fn(),
 }))
+jest.mock('./useCreateNewThread')
 jest.mock('@/extension/ExtensionManager')
 jest.mock('@/containers/Toast')
 
@@ -27,8 +27,13 @@ describe('useDeleteThread', () => {
     ]
     const mockSetThreads = jest.fn()
     ;(useAtom as jest.Mock).mockReturnValue([mockThreads, mockSetThreads])
+    ;(useSetAtom as jest.Mock).mockReturnValue(() => {})
+    ;(useCreateNewThread as jest.Mock).mockReturnValue({})
+
+    const mockDeleteThread = jest.fn().mockImplementation(() => ({
+      catch: () => jest.fn,
+    }))
 
-    const mockDeleteThread = jest.fn()
     extensionManager.get = jest.fn().mockReturnValue({
       deleteThread: mockDeleteThread,
     })
@@ -50,12 +55,17 @@ describe('useDeleteThread', () => {
     const mockCleanMessages = jest.fn()
     ;(useSetAtom as jest.Mock).mockReturnValue(() => mockCleanMessages)
     ;(useAtomValue as jest.Mock).mockReturnValue(['thread 1'])
+    const mockCreateNewThread = jest.fn()
+    ;(useCreateNewThread as jest.Mock).mockReturnValue({
+      requestCreateNewThread: mockCreateNewThread,
+    })
 
-    const mockWriteMessages = jest.fn()
     const mockSaveThread = jest.fn()
+    const mockDeleteThread = jest.fn().mockResolvedValue({})
     extensionManager.get = jest.fn().mockReturnValue({
-      writeMessages: mockWriteMessages,
       saveThread: mockSaveThread,
+      getThreadAssistant: jest.fn().mockResolvedValue({}),
+      deleteThread: mockDeleteThread,
     })
 
     const { result } = renderHook(() => useDeleteThread())
@@ -64,20 +74,18 @@ describe('useDeleteThread', () => {
       await result.current.cleanThread('thread1')
     })
 
-    expect(mockWriteMessages).toHaveBeenCalled()
-    expect(mockSaveThread).toHaveBeenCalledWith(
-      expect.objectContaining({
-        id: 'thread1',
-        title: 'New Thread',
-        metadata: expect.objectContaining({ lastMessage: undefined }),
-      })
-    )
+    expect(mockDeleteThread).toHaveBeenCalled()
+    expect(mockCreateNewThread).toHaveBeenCalled()
   })
 
   it('should handle errors when deleting a thread', async () => {
     const mockThreads = [{ id: 'thread1', title: 'Thread 1' }]
     const mockSetThreads = jest.fn()
     ;(useAtom as jest.Mock).mockReturnValue([mockThreads, mockSetThreads])
+    const mockCreateNewThread = jest.fn()
+    ;(useCreateNewThread as jest.Mock).mockReturnValue({
+      requestCreateNewThread: mockCreateNewThread,
+    })
 
     const mockDeleteThread = jest
       .fn()
@@ -98,8 +106,6 @@ describe('useDeleteThread', () => {
 
     expect(mockDeleteThread).toHaveBeenCalledWith('thread1')
     expect(consoleErrorSpy).toHaveBeenCalledWith(expect.any(Error))
-    expect(mockSetThreads).not.toHaveBeenCalled()
-    expect(toaster).not.toHaveBeenCalled()
 
     consoleErrorSpy.mockRestore()
   })
diff --git a/web/hooks/useThread.test.ts b/web/hooks/useThread.test.ts
index a40c709be6..4db7f87aca 100644
--- a/web/hooks/useThread.test.ts
+++ b/web/hooks/useThread.test.ts
@@ -78,7 +78,7 @@ describe('useThreads', () => {
     // Mock extensionManager
     const mockGetThreads = jest.fn().mockResolvedValue(mockThreads)
     ;(extensionManager.get as jest.Mock).mockReturnValue({
-      getThreads: mockGetThreads,
+      listThreads: mockGetThreads,
     })
 
     const { result } = renderHook(() => useThreads())
@@ -119,7 +119,7 @@ describe('useThreads', () => {
   it('should handle empty threads', async () => {
     // Mock empty threads
     ;(extensionManager.get as jest.Mock).mockReturnValue({
-      getThreads: jest.fn().mockResolvedValue([]),
+      listThreads: jest.fn().mockResolvedValue([]),
     })
 
     const mockSetThreadStates = jest.fn()
diff --git a/web/hooks/useUpdateModelParameters.test.ts b/web/hooks/useUpdateModelParameters.test.ts
index bc60aa631c..6c7ceb8b03 100644
--- a/web/hooks/useUpdateModelParameters.test.ts
+++ b/web/hooks/useUpdateModelParameters.test.ts
@@ -1,7 +1,12 @@
 import { renderHook, act } from '@testing-library/react'
+import { useAtom } from 'jotai'
 // Mock dependencies
 jest.mock('ulidx')
 jest.mock('@/extension')
+jest.mock('jotai', () => ({
+  ...jest.requireActual('jotai'),
+  useAtom: jest.fn(),
+}))
 
 import useUpdateModelParameters from './useUpdateModelParameters'
 import { extensionManager } from '@/extension'
@@ -13,7 +18,8 @@ let model: any = {
 }
 
 let extension: any = {
-  saveThread: jest.fn(),
+  modifyThread: jest.fn(),
+  modifyThreadAssistant: jest.fn(),
 }
 
 const mockThread: any = {
@@ -35,6 +41,7 @@ const mockThread: any = {
 describe('useUpdateModelParameters', () => {
   beforeAll(() => {
     jest.clearAllMocks()
+    jest.useFakeTimers()
     jest.mock('./useRecommendedModel', () => ({
       useRecommendedModel: () => ({
         recommendedModel: model,
@@ -45,6 +52,12 @@ describe('useUpdateModelParameters', () => {
   })
 
   it('should update model parameters and save thread when params are valid', async () => {
+    ;(useAtom as jest.Mock).mockReturnValue([
+      {
+        id: 'assistant-1',
+      },
+      jest.fn(),
+    ])
     const mockValidParameters: any = {
       params: {
         // Inference
@@ -76,7 +89,8 @@ describe('useUpdateModelParameters', () => {
 
     // Spy functions
     jest.spyOn(extensionManager, 'get').mockReturnValue(extension)
-    jest.spyOn(extension, 'saveThread').mockReturnValue({})
+    jest.spyOn(extension, 'modifyThread').mockReturnValue({})
+    jest.spyOn(extension, 'modifyThreadAssistant').mockReturnValue({})
 
     const { result } = renderHook(() => useUpdateModelParameters())
 
@@ -84,44 +98,46 @@ describe('useUpdateModelParameters', () => {
       await result.current.updateModelParameter(mockThread, mockValidParameters)
     })
 
+    jest.runAllTimers()
+
     // Check if the model parameters are valid before persisting
-    expect(extension.saveThread).toHaveBeenCalledWith({
-      assistants: [
-        {
-          model: {
-            parameters: {
-              stop: ['<eos>', '<eos2>'],
-              temperature: 0.5,
-              token_limit: 1000,
-              top_k: 0.7,
-              top_p: 0.1,
-              stream: true,
-              max_tokens: 1000,
-              frequency_penalty: 0.3,
-              presence_penalty: 0.2,
-            },
-            settings: {
-              ctx_len: 1024,
-              ngl: 12,
-              embedding: true,
-              n_parallel: 2,
-              cpu_threads: 4,
-              prompt_template: 'template',
-              llama_model_path: 'path',
-              mmproj: 'mmproj',
-            },
-          },
+    expect(extension.modifyThreadAssistant).toHaveBeenCalledWith('thread-1', {
+      id: 'assistant-1',
+      model: {
+        parameters: {
+          stop: ['<eos>', '<eos2>'],
+          temperature: 0.5,
+          token_limit: 1000,
+          top_k: 0.7,
+          top_p: 0.1,
+          stream: true,
+          max_tokens: 1000,
+          frequency_penalty: 0.3,
+          presence_penalty: 0.2,
         },
-      ],
-      created: 0,
-      id: 'thread-1',
-      object: 'thread',
-      title: 'New Thread',
-      updated: 0,
+        settings: {
+          ctx_len: 1024,
+          ngl: 12,
+          embedding: true,
+          n_parallel: 2,
+          cpu_threads: 4,
+          prompt_template: 'template',
+          llama_model_path: 'path',
+          mmproj: 'mmproj',
+        },
+        id: 'model-1',
+        engine: 'nitro',
+      },
     })
   })
 
   it('should not update invalid model parameters', async () => {
+    ;(useAtom as jest.Mock).mockReturnValue([
+      {
+        id: 'assistant-1',
+      },
+      jest.fn(),
+    ])
     const mockInvalidParameters: any = {
       params: {
         // Inference
@@ -153,7 +169,8 @@ describe('useUpdateModelParameters', () => {
 
     // Spy functions
     jest.spyOn(extensionManager, 'get').mockReturnValue(extension)
-    jest.spyOn(extension, 'saveThread').mockReturnValue({})
+    jest.spyOn(extension, 'modifyThread').mockReturnValue({})
+    jest.spyOn(extension, 'modifyThreadAssistant').mockReturnValue({})
 
     const { result } = renderHook(() => useUpdateModelParameters())
 
@@ -164,36 +181,38 @@ describe('useUpdateModelParameters', () => {
       )
     })
 
+    jest.runAllTimers()
+
     // Check if the model parameters are valid before persisting
-    expect(extension.saveThread).toHaveBeenCalledWith({
-      assistants: [
-        {
-          model: {
-            parameters: {
-              max_tokens: 1000,
-              token_limit: 1000,
-            },
-            settings: {
-              cpu_threads: 4,
-              ctx_len: 1024,
-              prompt_template: 'template',
-              llama_model_path: 'path',
-              mmproj: 'mmproj',
-              n_parallel: 2,
-              ngl: 12,
-            },
-          },
+    expect(extension.modifyThreadAssistant).toHaveBeenCalledWith('thread-1', {
+      id: 'assistant-1',
+      model: {
+        engine: 'nitro',
+        id: 'model-1',
+        parameters: {
+          token_limit: 1000,
+          max_tokens: 1000,
+        },
+        settings: {
+          cpu_threads: 4,
+          ctx_len: 1024,
+          prompt_template: 'template',
+          llama_model_path: 'path',
+          mmproj: 'mmproj',
+          n_parallel: 2,
+          ngl: 12,
         },
-      ],
-      created: 0,
-      id: 'thread-1',
-      object: 'thread',
-      title: 'New Thread',
-      updated: 0,
+      },
     })
   })
 
   it('should update valid model parameters only', async () => {
+    ;(useAtom as jest.Mock).mockReturnValue([
+      {
+        id: 'assistant-1',
+      },
+      jest.fn(),
+    ])
     const mockInvalidParameters: any = {
       params: {
         // Inference
@@ -225,8 +244,8 @@ describe('useUpdateModelParameters', () => {
 
     // Spy functions
     jest.spyOn(extensionManager, 'get').mockReturnValue(extension)
-    jest.spyOn(extension, 'saveThread').mockReturnValue({})
-
+    jest.spyOn(extension, 'modifyThread').mockReturnValue({})
+    jest.spyOn(extension, 'modifyThreadAssistant').mockReturnValue({})
     const { result } = renderHook(() => useUpdateModelParameters())
 
     await act(async () => {
@@ -235,80 +254,33 @@ describe('useUpdateModelParameters', () => {
         mockInvalidParameters
       )
     })
+    jest.runAllTimers()
 
     // Check if the model parameters are valid before persisting
-    expect(extension.saveThread).toHaveBeenCalledWith({
-      assistants: [
-        {
-          model: {
-            parameters: {
-              stop: ['<eos>'],
-              top_k: 0.7,
-              top_p: 0.1,
-              stream: true,
-              token_limit: 100,
-              max_tokens: 1000,
-              presence_penalty: 0.2,
-            },
-            settings: {
-              ctx_len: 1024,
-              ngl: 0,
-              n_parallel: 2,
-              cpu_threads: 4,
-              prompt_template: 'template',
-              llama_model_path: 'path',
-              mmproj: 'mmproj',
-            },
-          },
+    expect(extension.modifyThreadAssistant).toHaveBeenCalledWith('thread-1', {
+      id: 'assistant-1',
+      model: {
+        engine: 'nitro',
+        id: 'model-1',
+        parameters: {
+          stop: ['<eos>'],
+          top_k: 0.7,
+          top_p: 0.1,
+          stream: true,
+          token_limit: 100,
+          max_tokens: 1000,
+          presence_penalty: 0.2,
         },
-      ],
-      created: 0,
-      id: 'thread-1',
-      object: 'thread',
-      title: 'New Thread',
-      updated: 0,
-    })
-  })
-
-  it('should handle missing modelId and engine gracefully', async () => {
-    const mockParametersWithoutModelIdAndEngine: any = {
-      params: {
-        stop: ['<eos>', '<eos2>'],
-        temperature: 0.5,
-      },
-    }
-
-    // Spy functions
-    jest.spyOn(extensionManager, 'get').mockReturnValue(extension)
-    jest.spyOn(extension, 'saveThread').mockReturnValue({})
-
-    const { result } = renderHook(() => useUpdateModelParameters())
-
-    await act(async () => {
-      await result.current.updateModelParameter(
-        mockThread,
-        mockParametersWithoutModelIdAndEngine
-      )
-    })
-
-    // Check if the model parameters are valid before persisting
-    expect(extension.saveThread).toHaveBeenCalledWith({
-      assistants: [
-        {
-          model: {
-            parameters: {
-              stop: ['<eos>', '<eos2>'],
-              temperature: 0.5,
-            },
-            settings: {},
-          },
+        settings: {
+          ctx_len: 1024,
+          ngl: 0,
+          n_parallel: 2,
+          cpu_threads: 4,
+          prompt_template: 'template',
+          llama_model_path: 'path',
+          mmproj: 'mmproj',
         },
-      ],
-      created: 0,
-      id: 'thread-1',
-      object: 'thread',
-      title: 'New Thread',
-      updated: 0,
+      },
     })
   })
 })
diff --git a/web/hooks/useUpdateModelParameters.ts b/web/hooks/useUpdateModelParameters.ts
index 977ebd10be..dab2f6e284 100644
--- a/web/hooks/useUpdateModelParameters.ts
+++ b/web/hooks/useUpdateModelParameters.ts
@@ -82,6 +82,7 @@ export default function useUpdateModelParameters() {
         },
       }
       setActiveAssistant(assistantInfo)
+
       updateAssistantCallback(thread.id, assistantInfo)
     },
     [
diff --git a/web/screens/Thread/ThreadCenterPanel/AssistantSetting/index.test.tsx b/web/screens/Thread/ThreadCenterPanel/AssistantSetting/index.test.tsx
index 96ff6f559a..9b4e67ffbf 100644
--- a/web/screens/Thread/ThreadCenterPanel/AssistantSetting/index.test.tsx
+++ b/web/screens/Thread/ThreadCenterPanel/AssistantSetting/index.test.tsx
@@ -7,6 +7,8 @@ import { useAtomValue, useSetAtom } from 'jotai'
 import { useActiveModel } from '@/hooks/useActiveModel'
 import { useCreateNewThread } from '@/hooks/useCreateNewThread'
 import AssistantSetting from './index'
+import { activeThreadAtom } from '@/helpers/atoms/Thread.atom'
+import { activeAssistantAtom } from '@/helpers/atoms/Assistant.atom'
 
 jest.mock('jotai', () => {
   const originalModule = jest.requireActual('jotai')
@@ -68,6 +70,7 @@ describe('AssistantSetting Component', () => {
 
   beforeEach(() => {
     jest.clearAllMocks()
+    jest.useFakeTimers()
   })
 
   test('renders AssistantSetting component with proper data', async () => {
@@ -75,7 +78,14 @@ describe('AssistantSetting Component', () => {
     ;(useSetAtom as jest.Mock).mockImplementationOnce(
       () => setEngineParamsUpdate
     )
-    ;(useAtomValue as jest.Mock).mockImplementationOnce(() => mockActiveThread)
+    ;(useAtomValue as jest.Mock).mockImplementation((atom) => {
+      switch (atom) {
+        case activeThreadAtom:
+          return mockActiveThread
+        case activeAssistantAtom:
+          return {}
+      }
+    })
     const updateThreadMetadata = jest.fn()
     ;(useActiveModel as jest.Mock).mockReturnValueOnce({ stopModel: jest.fn() })
     ;(useCreateNewThread as jest.Mock).mockReturnValueOnce({
@@ -98,7 +108,14 @@ describe('AssistantSetting Component', () => {
     const setEngineParamsUpdate = jest.fn()
     const updateThreadMetadata = jest.fn()
     const stopModel = jest.fn()
-    ;(useAtomValue as jest.Mock).mockImplementationOnce(() => mockActiveThread)
+    ;(useAtomValue as jest.Mock).mockImplementation((atom) => {
+      switch (atom) {
+        case activeThreadAtom:
+          return mockActiveThread
+        case activeAssistantAtom:
+          return {}
+      }
+    })
     ;(useSetAtom as jest.Mock).mockImplementation(() => setEngineParamsUpdate)
     ;(useActiveModel as jest.Mock).mockReturnValueOnce({ stopModel })
     ;(useCreateNewThread as jest.Mock).mockReturnValueOnce({